I am trying to install some dependencies for flutter, which requires homebrew. The only problem is that homebrew does not install any tools.

For example, if I try both brew install --HEAD libimobiledevice, brew install ideviceinstaller and brew install ios-deploy, it gives me the following error (sometimes it is slightly different) and the tools do not install.

Last 15 lines from /Users/davidkeen/Library/Logs/Homebrew/makedepend/05.configure:
checking for rename... yes
checking for fchmod... yes
checking for special C compiler options needed for large files... no
checking for _FILE_OFFSET_BITS value needed for large files... no
checking for X... configure: error: in `/private/tmp/makedepend-20180609-57475-hh24w0/makedepend-1.0.5':
configure: error: The pkg-config script could not be found or is too old.  Make sure it
is in your PATH or set the PKG_CONFIG environment variable to the full
path to pkg-config.

Alternatively, you may set the environment variables X_CFLAGS
and X_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.

To get pkg-config, see <http://pkg-config.freedesktop.org/>.
See `config.log' for more details

Do not report this issue to Homebrew/brew or Homebrew/core!


Error: You are using macOS 10.14.
We do not provide support for this pre-release version.
You may encounter build failures or other breakages.
Please create pull-requests instead of filing issues.

Error: A newer Command Line Tools release is available.
Update them from Software Update in the App Store.


Error: You are using macOS 10.14.
We do not provide support for this pre-release version.
You may encounter build failures or other breakages.
Please create pull-requests instead of filing issues.

How am I meant to install these dependencies on macOS Mojave beta 1?

Please note that brew install cocoapods works, so I'm not sure if this is an issue with homebrew or package?